• 전자공학회논문지S
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• 제35S권4호
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• pp.85-95
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• 1998

In this paper, a new watermarking method for a copy protectionof images is proposed. The proposed method adaptively embeds a watermark in the frequency domain of images using human visual system model. For this purpose, the Just Noticeable Differences(JNDs) of each frequency coeffeicient value of a luminance plane is first found using Watson and Solomon's visual system model. An invisible maximum watermark value with is different in every position according to the characteristics of images is determined usig JND and Minkowski metric. A low frequency domain is divided into two sets based on a PN-sequence to protect thewatermark from the attack. The watermarks are added to one set of coefficients and detecting a watermark, the difference between the mean values of absolute coefficient values of both sets is calculated. The embedded watermark is tested using statistical hypothesis based on test static dertermined by the ean difference. To demonstrate the perfromance of the proposed method, the new watermarking method is applied to a high frequency image and low frequency images. Experimenatal results show the watermark is invisible and robust to JPEGlossy compression and noise.

• 한국가정과학회지
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• 제3권2호
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• pp.47-57
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• 2000

We study on the housewives'social contribution through their household labor. By the method of literature review, we discuss about the housewives'social roles, their negative problems and the private and public efforts to solve the problems, and ultimate direction to the solutions. We find their four roles-Invisible labors In this capitalist society. consumers without any sovereignty, substitutes for incomplete social welfare system and agents to develop and sustain the social network. A few solutions which they have found out or the Korean society has devised are not enough. The utmost and ultimate solutions should include the housewives'autonomy. subjectivity and community.

• 전자공학회논문지S
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• 제35S권7호
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• pp.86-94
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• 1998

The rosette-scan seeker is a device mounted on the infrared guided missile. It offers the positions and iamges of target to missiles servo system by scanning a space about target in rosette pattern with a single detector. An instantaneous field of view (IFOV), which is a diameter of a detector moving along the path of the rosette pattern, has the property that its smaller size provide the less interference of background signals and detector noise. If its size is too small to voer the total field of view (TFOV), however, it produces the invisible regions in the TFOV. In this case, the invisible regions cause the performance of the seeker to deteriorate. For full scan-coverage, it is necessary to design the small IFOV without the invisible regions in the TFOV, as possible. In this paper, we propose the new method of designing the smaller IFOV than the conventional method and verify full coverage of the scanned region. By comparing the nose equivalent flux density (NEFD) of the proposed method with the that of the conventional one, we confirm that the former is better than the latter in terms of performance.

• 한국지리정보학회지
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• 제12권3호
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• pp.66-75
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• 2009

본 연구는 개념으로만 정립되었던 불가시심도분석을 프로그래밍 기법을 통하여 도구화 하였다. 분석 알고리즘은 기 개발된 가시권분석 알고리즘인 참조판 방식(reference plane method)을 기본으로 시점과 가까운 곳에는 점대점 방식(point-to-point method)을 복합적으로 사용하였으며, 정밀도를 높이기 위하여 지구곡률반경에 의한 오차와 빛의 굴절에 의한 오차를 반영하여 광역분석을 고려하였다. 이렇게 재구성된 알고리즘을 이용하여 배포 활용이 가능한 ArcToolbox 도구 형태로 개발하여 사용자 편의성과 대중성을 고려하였고, 개발된 분석도구를 활용하여 사례대상지에 적용한 결과 기존의 수작업으로 할 수 없었던 고해상도 광역분석이 가능하였다.

• International journal of advanced smart convergence
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• 제9권3호
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• pp.207-214
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• 2020

Currently, the operation of unmanned aerial vehicle (UAV) is regulated to be able to fly only within the visible range, but in recent years, the needs for operation in the invisible area, in the urban area and at night have increased. In order to operate UAVs in the invisible area, at night, and in the urban area, a flight path for UAVs must be prepared like those operated by manned aircraft, and for this, it is necessary to establish an unmanned aircraft system traffic management (UTM). In order to establish the UTM, information on the minimum separation distance to prevent collisions with UAVs and buildings is required, and accordingly, information on the navigation performance of UAVs is required. In order to analyze the navigation performance of an UAV, total system error (TSE), which is the difference between the planned flight path and the actual location of the UAV, is required. If the collected data are insufficient and classification according to integrity, independence, and direction is not performed, accurate navigation performance is not derived. In this paper, propose a navigation performance analysis method of UAV that is derived TSE using flight data and modeled with normal distribution, analyze performance.

• 한국전자통신학회논문지
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• 제6권3호
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• pp.371-379
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• 2011

본 논문에서는 입체 영상 디스플레이 시스템 환경 하에서 다중의 사용자가 입체 영상 내의 사물과 상호작용이 가능한 입체 인터랙티브 콘텐츠 시스템 개발 방법을 제안한다. 상호작용을 위한 방법으로는 최근 대중적으로 많이 보급된 멀티터치 방식을 이용하여 사용자의 제스쳐 정보를 입체 영상 환경 하의 사물에 적용한다. 기존 멀티터치 방식은 디스플레이 표면과의 직접적 접촉을 통해 상호작용이 발생하나, 입체 영상의 경우 디스플레이 표면과 참여자 간의 적정 거리가 떨어져야 한다는 제약조건으로 기존 방법을 적용하기 어렵다. 이를 해결하기 위해 공간 상에 상호작용을 위한 비가시성 표면을 생성하고, 생성된 표면과 참여자의 신체와의 접촉을 상호작용의 이벤트로 간주한다. 또한 본 논문에서는 상호작용이 가능한 입체 영상 저작을 위해 게임 엔진 기반의 입체 영상 생성 및 편집 기법을 제시한다.

• 도서관문화
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• 제18권5호
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• pp.19-27
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• 1977

이 글은 Glynn Harmon이 Annual Review of Information science and Technology (The American Society for Information Science: Vol. 11, 1976, pp.347-380)에 발표한 ‘Information Science Education and Training'을 지면상 초역한 것이다. Harmon 교수는 현재 Texas대학 대학원에서 연구방법론과 정보과학을 강의하고 있으며, ’On the Evolution of Information Science(1971)' 'Human Memory and Knowledge : A System Approach (1973)' 'The Invisible Manpower Market for Information Scientists 91975)' 등의 논문을 발표하였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(2)
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• pp.87-90
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• 2002

A digital watermark is an invisible mark embedded in a digital image which used for copyright protection. In this paper, we propose a new optical watermarking system. A optical watermarking system is applied for digital watermarking by phase hologram and Mach-Zehnder interferometer. A optical watermarking technique to be hidden is phase modulated in a random patten, and its Fourier-transformed hologram image is superposed on a content image. The autentication information extract by using Mach-zehnder interferometer.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(1)
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• pp.227-230
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• 2002

A digital watermark is an invisible mark embedded in a digital image which used for copyright protection. In this paper, we propose a new optical watermarking system. A optical watermarking system is applied for digital watermarking by phase hologram and Mach-Zehnder interferometer. A optical watermarking technique to be hidden is phase modulated in a random patten, and its Fourier-transformed hologram image is superposed on a content image. The autentication information extract by using Mach-zehnder interferometer.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 ITC-CSCC -2
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• pp.1092-1095
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• 2000

Computer graphics(CG) is one of the most useful tools by which we can easily understand visible/invisible natural phenomena. Namely, phenomena in the universe is attractive one because of its beauty and invisibility on the earth. For gravitational tensing phenomena, a ray tracing algorithm is proposed based on a lens-plane. In the method, position of gravitational sources is restricted. In this paper an improved visualization method is proposed, which can represent more complex situation than the previous method.